In addition to a good level of efficiency, this type of dual-clutch transmission has the advantage, among other things, that it can be engaged, particularly in an automated manner, without interrupting the tractive force, whereby, in the non-activated sub-transmission, a gear can already be preselected, which is then activated by switching the power-shift clutches. In doing so, the odd gears (1, 3, 5, etc.) in one sub-transmission and the even gears (2, 4, 6, etc.) in the other sub-transmission are positioned by means of corresponding gear wheel sets, which are drivingly connected to the respective input shaft or the output shaft, for example, via synchronous clutches.
The axial length of the dual-clutch transmission depends on the number of gear wheel sets or wheel planes, which are arranged in the axial direction behind one another in the dual-clutch transmission. Each of the wheel planes is constructed of at least two fixed and/or detached gear wheels. Shift elements, upon the activation of which forward and reverse gears can be engaged, are arranged between the wheel planes.
A generic dual-clutch transmission has gear wheel sets, which form, in particular, precisely eight wheel planes, which can be engaged by way of shift elements. The wheel planes are allocated to a first sub-transmission and a second sub-transmission, respectively. Each of the sub-transmissions has an input shaft as well as a common output shaft. The input shafts, which are coaxial with respect to one another, can be activated in an alternating manner by way of a power-shift clutch, wherein the even forward gears are allocated to the first sub-transmission and the uneven forward gears are allocated to the second sub-transmission, which can be engaged during a gear change by way of the shift element. Each of the wheel planes here provides a direct gear in which precisely one wheel plane is engaged in the torque flow extending through the activated sub-transmission.